Connection for lagging irons



1960 K. M. GROETSCHEL 2,959,924

IN VE N 70R 07% gay-mm 3 Sheets-Sheet 1 v NOV. 15, 1960 GRQETSCHEL 2,959,924

I CONNECTION FOR LAGGING IRONS Filed March 8, 1955 r 6 3 Sheets-Sheet 2 I 29 :W t

. IN VENTOR 7?.2 02m j/w-efickal 1960 K. M. GROETSCHEL 2,959,924

CONNECTION FOR LAGGING IRONS Filed March 8, 1955 3 Sheets-Sheet 3 INVENTOP Won! AodialJ United States Patent 2,959,924 7 CONNECTION FOR LAGGING IRONS Karl Maria Groetschel, 3-5 Schutzenbahn, Bochum, Westphalia, Germany Filed Mar. 8, 1955, SerfNo. 492,914

Claims priority, application Germany Apr. 3, 1954 18 Claims. or. 61-45 The invention relates to lagging irons for the lagging of mines, having lock componentsengaging with one another in the manner of a fork and tongue and connected with one another rotatably about a horizontal axis, the said lagging irons being adapted to be locked with respect to one another in any angular position within the range required, by means of a transversely slidable element. Such lagging irons are firstly advanced cantilever-fashion, as members of an assembly, then they are supported by props in accordance with the advance of mining, and eventually removed again on the side of the gobbing.

The invention has the object of developing such lagging iron connections in such a manner that on the one hand the use of lagging irons provided therewith is possible in one position as well as in a position turned 180, and that on the other hand in each of these two positions locking is possible at will in one direction or in the opposite direction, without requiring, as in the known designs, either two transversely shiftable locking elements or one element only, which then had to be inserted from different sides at any time. Moreover it is an object of the invention by suitable development of such connections to provide the possibility of restoring the freedom of articulation of the connection in a controllable manner advantageous to the saving of the lagging irons and particularly the lock members of the roof.

This is attained according to the invention substantially by a novel design of the locking element which is formed by a transverse plate shiftable in the lock of the lagging irons and formed complementary to the front end of the tongue on which it is mounted, such that this transverse plate has an oblique ridge going right through from one of its ends to the other and having two abutment faces, one of which co-operates with one of two counter-faces formed by a recess in the end of the tongue in one of the two positions of the lagging iron, and of which the other co-operates with the other one of the said counter-faces when the lagging iron is turned through 180. I

This transverse plate is provided at both its ends with abutments limiting the extent of its transverse displacement and preventing it being removed from the lock altogether.

Preferably the recess in the end of the tongue of the lock and accordingly the oblique ridge of the plate cooperating therewith are so constructed, that when one of the abutment faces contacts a counter-face of the tongue, such a play is present between the other opposite abutment face of the ridge and its associated counter-face in the tongue, that the plate can be shifted from its locking position to a considerable extent before the tongue is locked in the opposite direction by the second face of the plate which comes into contact with its associated counter-faces in the tongue.

After the lagging iron, which had firstly been advanced cantilever-fashion, has been supported by a prop,

the possibility is thereby established of restoring the freedom of articulation of theconnection by an approa Patented Nov. 15, 1960 priate displacement of the plate for the purposeof abolishing its rigidity to the extent required for forestalling the danger of damage to the lock components in the case of excessive loading, as well as conversely restoring rigidity if necessary in the opposite direction upon changing action of pressure. p a

The abutment faces of the oblique locking ridge have to be adapted to the counter-faces at the end of the tongue, which are likewise arranged obliquely and run in the longitudinal direction of the lagging irons, being however preferably designed straight, insucha manner that if possible in every attachment position of the lagging irons, whether stretched out or angularly deflected, the largest possible area of contact between the engagement points is established. -This involves. a certain twisting of the operative faces of the locking ridge l fii According to anothr embodiment the mutually correa sponding faces of the locking ridge, and of the tongue, I

could be so profiled that the engaging components mesh with one another in the approximate manner of an involute, cycloid or similar toothing. Thereby, however, a

no large area contact is attained, but yet an excellent line contact of the engaging components, which is quite suflicient when using materials of appropriate quality, since in all vertical angular positions of the lagging irons this line contact remains constant.

In a further development of the invention, when the I bilaterally symmetrical formation of the lock elements is dispensed with, one of the two contact faces of the end of the tongue and/or of the locking ridgescanbe" arranged at a larger distance from the axis of the laggin'g. iron than the other. Thereby it is made possible to keep the aforesaid play between the locking elements'parr, ticularly large, if desired, which play is required for restoring the mobility of articulation of the connection] I after the lagging iron has been supported by a prop,

without curtailing the extent of possible angular deflecw tion in one of the turned positions of the lagging iron,

so that the operational characteristics of the lagging iron in this position are kept fullypreserved, and are some: what reduced merely in the opposite turned positionl Q It may be found particularly advantageous to dimension the play between'one of the front edges or fa'ces; of the end of the tongue or of such a locking ring "or, of

the bolt, respectively, so small, that the lagging iron which, when being fitted, is pushed with its tongue firstly,

\ from a downwardly inclined position over'the locking ridge and which is thereby resting on the latter and adapted to be tilted up, abuts onto the locking ridge or onto the plate itself in such a manner, that in the case of connection of the two irons by means of a joint pin'jthe direction of the butt joint in the two lock elements results in a predetermined position of the 'laggingirontdbe advanced, preferably in a position somewhat below the stretched out position. This allows a labour-saving en'- gaging, in a fraction of a second, of the lagging iron'byi means of the joint pin, whereupon the operator is immediately relieved from the weight of the lagging iron and is safeguarded, since the connection is already locked by the resting in of the tongue into the locking ridge which likewise takes place automatically when putting on the lagging iron. The operator can then if necessary stop, before he corrects the advanced position of the lagging iron by further pushing or driving of the plate into the lock.

In order that the lagging iron may be advanced in a labour-saving manner, even in mine workings in which,

because of a larger height of the coal face bay or of too;

for the purpose of tilting up the lagging iron is no longer possible or not advisable, the lagging iron lock designed;

in the manner described can be provided with simple means which allow it to be tilted up after having been temporarily suspended cantilever-fashion.

As auxiliary means of this kind there may be provided in a known manner, for example, on the tongue, a special recess,such as a push-through bore or the like, preferably however a notch formed by a hook-shaped member, which according to a particular feature of the invention, cooperates with a device arranged on the fork, for example a push-through pin, in such a manner that during the tilting up of the lagging iron about the pin as the pivot axis, the tongue, is made to rest in forcibly with the locking ridge, so that by a mere pushing in of the joint pin into the lock at the moment when the bolt holes register, the cantilever connection of the lagging iron can be established in a position which corresponds largely to the final advanced position.

The pores provided in the prongs of the fork for tale ingin the push-through pin have a comparatively small diameter in view of the weakening of the fork that would otherwise occur, for instance the push-through pin is not made very strong so that it could be bent or shorn off by lever action which takes place when inadvertently the lagging iron is tilted up beyond the position in which the bolt holes register with one another and causing the tongue to hit the bolt too hard.

In order to prevent this, according to a further feature of the invention a device is arranged on the lock which indicates the exact coupling position of the two lagging irons with respect to one another in any one of the two turned positions and/ or secures the same by an abutment, for example in the form of markings provided on the tongue and on the fork which correspond with one another in the accurate coupling position of the lagging irons, preferably in the form of abutments, resting-in means or the like. According to a special form of construction these abutments may be formed on the one hand by a loose locking member adapted to be arranged on the tongue, preferably a further push through pin, and on the other hand a projection or the like arranged on the prongs of the fork, on which this locking member abuts when the coupling position is reached.

According to a further embodiment the indicator and/ or safety device may alternatively be formed by a resting-in means in the form of a spring bolt or the like, capable of being put out of action, arranged at one part of the lock (either the fork or the tongue), and of a rest corresponding to this means arranged on the other part.

All the auxiliary means that have been proposed for facilitating the fitting in of the lagging irons are to be provided in a double or double-acting arrangement in such a manner that they can serve their purpose in both turned positions of the lagging iron.

According to a further embodiment, the transverse plate may, instead of the obliquely directed locking ridge running right through, have alternatively two locking ridges, running parallel to one another and equally profiled, inwhich case then in an inverse arrangement so that it is not the outward faces, but the inner faces of these two ridges which form the active faces, and cooperate with a projection at the end of the tongue rather than with a recess of appropriate shape.

The basic principle of operation of this modified embodiment is inherently the same as that of the one described first. Although it is not as advantageous in every respect, particularly in respect of the operating of the lagging iron, it has on the other hand the advantage that the effective face running obliquely in the direction transverse of the lagging iron inaccordance with the obliqueness of the ridges of the plate can be arranged more easily on the projection of the tongue than those of the recess of the tongue.

In order to be able to vary the possibilities of angular deflection and other properties of the lock, preferably on the Site itself, and thus to adapt the connection in every Cir particular case to the conditions prevailing, according to a further feature of the invention several mutually interchangeable transverse plates can be used at will, each of which has for example a different length or is provided with a differently profiled locking ridge or double ridge or has a different design adapted in another respect to the varied conditions, and at the same time optionally on the tongue, a correspondingly interchangeable piece may be provided arranged on the tongue an adaptation of the profile of the recess or of the projection on the end of the tongue is required to such a modified shape of the locking ridge of the bolt actually inserted.

According to a particular feature of the invention the transverse plate can be so constructed that their locking ridge is interrupted in its middle range to a distance which permits the passage of the end of the tongue, the two parts of the ridge being then preferably somewhat offset with respect to one another. Such a transverse plate permits at its middle position the free tilting of the advanced lagging iron and particularly the establishing of a perfect freedom of articulation of the connection after the advanced lagging iron has been supported by a prop, and moreover permits the lagging iron to be tilted downwardly about the pin on the last iron not yet dismantled on the gobbing side.

With basically the same effect the exchangeable plate may alternatively have a pair of ridges consisting of two part-pairs, between the inner ends of which a gap is provided which permits the passage of the tongue.

It has been found convenient in the construction of a lagging iron connection as described hereinbefore to design the locking element, that is the plate, and/or the coupling element-the pin-in such a manner that the connection is made thereby yielding to a certain extent in case of overloading.

Thisin connection with the advantage of saving material and accordingly weightis attained according to a further feature of the invention in that the locking and/or coupling element while retaining its functionally required basic dimensions is at least partly provided with a recess or the like into which the material of the Work piece stressed at the abutment faces escapes when exceeding a certain overload. This principle can be realised, for example, in the coupling pin in that the same is made hollow and has a longitudinal slot. In the same sense the oblique ridges can be made hollow at, least partly so that a corresponding groove is formed at the back of the plate. It is particularly advantageous when the pin or plate designed as described hereinbefore is made of spring steel or of a material having properties corresponding to those of spring steel.

It is particularly advantageous from the point of view of the possibility of readily dismantling the lagging iron on the gobbing side, when the wedge surfaces are offset with respect to each other, in such a manner that in continuation of the upper end of the wedge face actually on top as well as in continuation of the lower end of the wedge face actually on the bottom, a gap is formed which opens upwardly and downwardly, respectively, which permits the passage of the tongue, while on the other side the wedge surfaces extend right to the end of the plate.

This embodiment involves a shorter length and reduced bulkiness of the locking element, which is particularly advantageous in the case of a small lateral distance of the laggings. Moreover it makes it possible to bring the plate out of its engagement with the tongue even without previous loosening of the connecting pin, so that the lagging iron to be dismantled can swing downwardly pendulum-fashion, before being eventually dismantled.

In cases in which the individual rows of laggings have to be set at small distances from one another, it may be of advantage to make the bolts curved in the direction towards the coal face. Plates curved in this manner are more easily operated in confined spaces than the straight plates, and offer in certain circumstances some advantages from the point of view of the desirable abutting of the effective faces of the engaging components as closely as possible.

In-order to allow the interchange of the plates on the site, the means securing the locking plate on the lock against being completely detached are so constructed that it can be put out of action without having to damage or to remove the same.

For this purpose the safety device may for example consist of an adjustable member co-operating with two abutments provided on the plate preferably through intermediate pieces, which member isaccessible through a bore provided on the plate or the like to an operating tool, preferably to a special tool. The last arrangement has the advantage that, as may be desirable, only certain persons equipped with the special tool are capable of removing the plate from the lock.

Such a device may be constructed according to a further embodiment of the invention in such a manner that it permits, in addition to the safety task, a controllable braking of the plate, and it may for this purpose be placed under the action of a reinforced resilient intermediate piece, preferably a rubber ring or the like.

This resilient intermediate piece and its reinforcing body, consisting preferably in a pin, washer or capsule, are preferably movably connected to the safety means adjustably arranged on the root of the fork of the lock, or is movably mounted in the fork, for example by means of a threaded pin or the like engaging into a lateral slot provided thereon, and thereby secured against falling out. q

In order to prevent .theiron falling when dismantling, the lagging iron is assembled according to the invention after the loosening of the pivot pin and the subsequent disengagement of the mutually co-operating components,

thelocking ridge and tongue, preferably the two locking irons are easily detachably connected with one another by a chain, which is attached on a preferably stirrupshapeddevice mounted on the fixed lagging iron, while the chain carried by it is simply hooked into holes of the lagging iron to be dismantled. t I

The stirrup-shaped device may serve at the same time aslan abutment for a lever adapted to be inserted between the components of the lock, by means of which the lagging iron can be forced out, in case it should not detach itself automatically from the oblique face of the tongue after the looseningof the connecting pin.

Inthe most frequent case, in which the use of such a stirrup can be dispensed with, this lever may be pro-.

vided and used per se in order to effect the forcing apart. and disengaging of the lock components in principally the same manner, by engaging themdirectly on the lagging iron. l

According to a modified embodiment 'of the invention, for the same purpose instead of the lever an elongated hole may be provided at the placeion which otherwise the hole intended for receiving. the, stirrup is provided,

into which elongated hole after the loosening the coupling pin a transverse wedge is driven, which forces thelagging iron to be moved away and loosens-the same from its engagement with the subsequent lagging iron. 1

Since it has been frequently found difficult to operat the locking element when fitting comparatively long lagging irons, because the man who fits in the lagging iron finds himself at the end thereof adjacent the coal face out of reach of the lock, the arrangement can be made according to a further feature of the invention in such a manner,v that the coupling and/or locking elements are brought into and out of their effective position by the action of means applying a pressure or pull on them.

According to a preferred embodiment of the invention, a locked element serves as such a means, which ispro vided between a stationary point and one endof the coupling and/or locking element which element is under load, and which drives'the coupling and/or locking, element into the coupling and/ or locking position when loosening the locking of such locked element.

For this purposefor example a spring bar or the like can be used, which engages with its one end on the lagging iron to be fitted, preferably on the lagging iron carrying the coupling and/or locking element, and with its loaded other end engages the coupling and/ or locking element. Instead of this spring rod alternatively a coiled spring, a strongly resilient rubber body, a compressed air pin or the like can be inserted.

According to a preferred embodiment of the invention the release of the elements under load is effected in that with an appropriate design of the mutually co-operating lock components the entrance passage for the transversely shiftable locking elements, previously blocked by a part of the lagging iron itself, is automatically cleared by the vertical tilting of the lagging iron to be advanced.

The additional device described last is basically usable in an entirely similar manner, which has merely to be adapted suitably, to the insertion of the joint pin as well as of the locking elements, n'amely of any construction desired, in the case of its beingused for pushing in the pivot pin, preferably a device known in itself in the form of a transverse pinadapted to be pushed through is providedvon the lagging iron, on which the lagging iron to be advanced is firstly suspended in order to be swung up about the axis thereof, in such a manner that in the course of this movement the plate holes are forcibly brought into juxtaposition.

In the drawings the lagging iro-n connection according to the invention and its individual features are shown in their principal embodiments.

Figures 1 and 2 show a partly sectional lateral and planview respectively of part of two lagging irons. coupled together according to one embodiment of them:

vention; a

Figure 3 shows a first elevation of a part of Figures 1 and 2; a

Figure-4 shows an end elevation of a part of Figures 1' andZ; t

Figure 5 shows a modification, inside, partly sectional elevationof the embodiment of Figuresl and 2;

Figure 6' illustrates the manner of forming the coupling shown in-Figures 1 and 2, and is a lateral, partly secitonal simplified view similar to that Figure l;

Figure'7 shows a lateral, partly sectional view of a modification of Figures land 2;

Figure 8 shows an elevational view of a. safety device 7 when n for use in the embodiments of Figures 1, 2 and a lagging iron is'to be decoupled; 1

Figure 9 shows a side elevational, partlysectional view- Figure 11 shows a side elevational, partly sectional. view of the tongue of a lagging iron engaging in the lock ing element of Figure 10;

Figure 12 shows a top plan view of another formof locking element;

Figures 13 to 15 illustrate a device for forcing the lockin the ing element into and out of its operative position lagging iron couplings of the invention;

Figure 13 is a side elevational, partly sectional view of.

Figure 14 shows a side elevational diagrammatic vie 2 part of two coupled lagging irons;

of the device in operative position; I I

Figure 15 shows the position of the device when locking element has been pushed in; and

Figure 16 shows a side elevational diagrammaticgview of a modification of the device of Figures 13m 15. i

In Figures 1 to 4, the tongue'welded to the end'of the: lagging iron 1 facing towards the. gobbing is denoted}, ,J

the fork welded to the lagging iron 4 is denoted 3, and the pivot pin is denoted '5, which establishes the vertically movable joint. The connection is made rigid in the downward direction as illustrated by a transverse plate 6, the locking ridge 7 of which, shown in Figure 3 in front elevation, engages into the recess 9 provided at the end 8 of the tongue 2, which is shown in Figure 4 in lateral elevation, in that the lower efiective face 10 of the recess of the tongue abuts on the lower effective face 11 of the locking ridge 7, while between the effective faces 12 of the recess of the tongue on the one hand and the effective face 13 of the ridge 7 on the other a free gap is left, which affords a limited freedom of articulation to the connection in the opposite direction.

Aswill be clear from these figures, the effective faces of the tongue running obliquely in accordance with the oblique position of the locking ridge of the plate are plane faces, while those of the locking ridge are somewhat warped. In the Figures 1 and 2 the profiled hole is denoted 14 in which the plate 6 is forcibly guided while there is a free passage of the oblique locking ridge 7, in that its upper and lower edges engage into special recesses of the hole 14. In Figure 2 it is indicated in chain-dotted lines, how the plate 6 may alternatively be shaped curved for the purpose of easier servicing in confined spaces, which presupposes of course a corresponding guide of the plate in the lock. At the ends of the plate, flanges 15, 15' may be shaped as abutment heads for the percussion tool serving for driving in the plate. They are so designed that they do not hamper the insertion of the plate into the hole 14 or its entire detachment from the lock.

In order to secure the plate in the lock, as shown in Figure 2, abutment-s 16, 16' are arranged at the rear of the flanges 15, 15 on the plate. These abutments cooperate with the safety device arranged at the root of the fork, the adjustment screw 18 of which is accessible to the operating tool through the bore 17 provided in the bolt. In co-operation with the annular rubber insert 20, which is protected by a cup-shaped reinforcement 19 and which is connectedto the head of the adjustment screw and is displaceable by the latter, this device allows alternatively the safety means to be put out of operation for the purpose of exchanging the plate for another one as well as a controllable braking of the bolt, which braking can also be made ineffective. The braking is of particular importance when using the lagging irons on coal faces of sloping down seams, in order that any possible loosening of the plate, here obliquely positioned by any shaking of the rocks. Also when transporting the lagging irons, this braking action may be advantageous, but in other cases it may be detrimental so that the means must be provided for putting it out of operation. The possibility of controlling the braking attained by the device may be of great importance when owing to extreme smoothing of the guide of the plate, either through repeated use or through coal dust which has got in and acts as a lubricant, or owing to a larger inclination of the locking ridges, there exists the possibility of exceeding the self-locking of the plate in the lock. In order to attain if necessary a particularly strong braking action, it is convenient to arrange on the plate itself and/or on the side of the reinforcement of the rubber ring facing the same, a lining having a high frictional coefficient.

Figure shows the arrangement of a locking ridge and tongue with unilaterally enlarged play between the noncontacting effective faces 12' and 13' for the purpose of particularly enlarging the range of freedom of articulation of the joint, after the lagging iron has been supported by a prop. It moreover shows the profile of all four effective faces of the kind of gear toothing. From the figure moreover the construction of the coupling pin of the locking element as described hereinbefore can be seen which serves for attaining .a certain yielding upon overloading by deliberately iprovidingia weakspot. For

8 this purpose according to the'embodiment the pin 46 is made hollow and has a longitudinal slot 47. The plate, too, is made hollow as shown at45.

Figure 6 illustrates the connection according to Figure 1 in that position of the components with respect to one another which results after the lagging iron 1 has come to rest with the upper effective surface of the recess in the tongue, firstly on the locking ridge of the lagging iron 4, and has then been tilted up on the locking ridge until the upper point of the tongue 21 abuts on the plate and thereby has been brought in the axial direction and can be forced into the position of juxtaposition of the bolt holes 22, 23. Any jamming of the engaging components owing to the butt joint is not to be feared since after the pushing in of the joint pin the play determined by the tolerances between the latter and the bolt holes relieves any such jamming. The manner of fitting deter mined thereby saves labour and allows an extraordinarily quick advance, is mainly applicable under favourable local conditions.

Figure 7 illustrates by way of example how with the use of the auxiliary means proposed even in unfavourable spatial conditions, the lagging irons can be brought in a particularly labour-saving manner into the position of juxtaposition of the bolt holes. As indicated bychaindotted lines, the lagging iron 1' is suspended, firstly with the hook-shaped extension 25 which forms a recess 24 on the lower side of the projection of the tongue, from a low position, in the extreme case from a position extending vertically downward, on the push through pin 27 inserted in a hole 26 arranged in the prongs of the fork of the lagging iron 4'. In the subsequent tilting up of the lagging iron suspended in this manner the recess of the tongue and the locking ridge 7' are forcibly made to rest in one another, and the bolt holes are made to register with one another, in the case illustrated in a position of the lagging iron l' yet angularly deflected downwardly.

This angular position should preferably correspond to the lowest possible angular position of the advanced lagging iron. After the tilted-up lagging iron has been coupled in by pushing in the pin 5 the position of the lock components as illustrated results in that owingto the out-of-balance weight of the lagging iron 1 which is no longer held by the operator with respect to the tongue the lower locking ridge comes into contact, whereby the push through pin 27 is again released by the hook 25. Then the operator, after having removed the push through pin 27 again, can bring the lagging iron 1' into the advanced position by further tilting the same up and at the same time pushing in the bolt, or merely by driving in the bolt.

In the inverse position of the lagging iron or of both lagging irons, for the use of the push through pin 27 members 24', 25 and 26' are available which are arranged opposite the members 24, 25 and 26 in the same sense, as will be seen.

In order to obviate any unintentionally high tilting up of the lagging iron 1 suspended on the push through pin, as a consequence of which the push throughpin may be bent or sheared off as indicated in Figure 7 in chaindotted lines, markers 28, 28' are provided on the tongue, the upper one of which, according to the turned position of the lagging iron, indicates at any time to the operator the position in which the bolt holes register, when they are, in juxtaposition with the marker 29 provided on the fork of the lagging iron 4'.

The same figure illustrates also a basic embodiment of a device which not merely indicates the correct coupling position of the lagging iron, but securesthe same also upwardly. The same consists asshown in two bores 30 and 30 on the tongue to be used alternately and in a pin 31 to be inserted into the same, which limits the pos sibility of tilting up the lagging iron into the position in which the bolt holes register with one another, by the abutting of the projection 32 arranged on the frontof the prongs it of the-fork againstthe edge which is actually the effected. The two pins 27 and 31 are preferably connected with one another by a chain.

Figure 8 shows per se the safety device for preventing any dropping out of the lagging iron to be dismantled.

Figure 9 shows the same device in an arrangement mounted on the lagging iron.

. As will be seen this device can be fitted by pushing its stirrup-shaped hook 33 into the bore 35 provided on the tongue of the lagging iron 34 in such a way that it is easily detachable by knocking out, and the hooks 36, 36 attached on this stirrup by means of'chains can be hooked into the lagging iron to be dismantled, the said hooks being preferably normal. The pushed in stirrupshaped hook 33may serve at the same time as an abutment for a lever 38 which can be applied between the components of the clock, by means of which the lagging iron 37 can be forced out if it should not detach itself automatically from the oblique face of the tongue after loosening the pin 39. When the occurrence of such a case is to be expected beforehand, the lever is preferably applied and operated before the loosening of the pin so that the force derived from it can act on the lagging iron 37, which at this moment is still suspended freely, at the moment when the pin releases the lagging iron 37.

The, possibility of detaching the two lagging irons in the alternative manner described hereinbefore from their engagement with one another by driving a wedge 44 into an elongated hole 43 in the tongue of one of the irons, is illustrated in Figuresl and 2.

Figures 10 and 11 show on a smaller scale an embodiment of theplate having two parallel locking ridges 40, 40', and the construction of the tongue resulting therefrom. The latter engages, as shown in Figure 11, into a groove running obliquely as formed by the ridges while leaving the play according to the invention. This construction of the plate and of the tongue allows a simpler design of the tongue, but does not allow the advantageous application of the auxiliary means shown in the embodiment of the lagging iron connection according to Figure 7 for the labour-saving tilting up of the lagging iron to be advanced. Moreover the bolt provided with the double ridge increases the weight of'the lagging iron. All the other advantages of the invention are however attainable in almost the same manner with this embodiment.

Figure 10 shows also, indicated by 42 and 42' and delineated by chain-dotted lines, the shortening of the ridges 40 and 40, in an arrangement in which each of them lieswith one of its ends opposite that of the other and which serves for the purpose of allowing the tongue to emerge from its locking when the bolt is pushed back, so that then the lagging iron to be dismantled on the gobbing side can swing down pendulum-fashion. In this case the outer ranges, limited by the chain-dotted lines, ofithe ridges 40 and 40" are dispensed with.

Figure 12 shows, likewise on a smaller scale, a plate which can be used at will in exchange with the plate according to the Figures 1 to 3, the locking ridge of which is interrupted in the middle range, and the two obliquely running part-ridges 41 and 41' thus formed are arranged offset from one another. The interruption is so dimensioned that a free passage of the tongue of the lock is made possible between the part-ridges. According to the turned position of the lagging iron, to which the other one'is to be attached, preferably at any time, that ridge is used which lies on the right hand side. This construction allows by entirely disengaging that part-ridge which actually is the lower one, after the propping up of the advanced lagging iron, to make the connection a freely movable joint without limitation, if necessary, so that moreover even tilting down and letting the lagging iron hang on the pivot pin is made possible.

.7 Figures 13 to 16 illustrate embodiments of devices 10 which serve for moving the locking element into and out of its operative position in the lock by applying a me chanical pull or push to the same.

Figures 13 to 15 show a lagging iron lock of the kind illustrated in principle in the previous figures, consisting of the fork 51, of the lagging iron 52 which is to be assumed as propped up, and of the tongue 53 of the lagging iron 54 to be advanced, as well as the coupling pin 55 and of the fixing plate 56, which co-operates by its oblique ridge 57, with a face of the oblique gap 58 of the tongue 53. In the eyes 63 arranged on the fork 51 the two coiled springs 62 are hooked, one of which is arranged to the right and one to the left of the linkage 60, the said spiral springs being attached on the grip 59 of the said linkage 60 of the pushing-in device which engages with its point the head 61 of the plate 56, the said linkage being adapted to the push-in path of the plate 56.

Figure 14 shows the device in thestate of loading in readiness for working. In order to push the plate 56 projecting from the fork 51 into the lock, the device is triggered off in that the lagging iron 54 which in position illustrated in Figure 13 in full lines clamps the bolt'by its tongue to be swung by the fitter up into its position indicated in chain-dotted lines, whereby the path into the lock is cleared for the plate. I

Figure 15 shows the device in its relaxed condition that is after the released plate has been pushed into the end position of the plate, merely by releasing the lagging iron again.

After terminating the pushing-in operation of the bolt, the relaxed pushing-in device can again be taken off in order to be used for the fitting of the next lagging iron lock. For this purpose the device is hooked to thelatter into the eyes 63, after the plate 56 has been pulled out in accordance with Figure 14, and the cap to be advanced has been brought into the provisional position illustrated in Figure 13 and has been coupled by means of the pivot pin 55.v Thereafter the device is tensioned by pulling the grip of the linkage 60, and is brought into its operative position by pushing the point of its linkage into the head of the bolt. 6 X

In an appropriately similar manner the same push in device may be used also for the mechanical'insert ion of the coupling pin 55 into the lock of the lagging irons, .when, as indicated in Figure 14 in chain-dotted-lines, an eye 63 or the like is provided on the fork. V For this howeverthere is .the condition that the lagging iron to be advanced can rest with its tongue on the ridge 57 of the plate 56 and withits other end on the sole at suchan angle that while the device is tensioned by the operator,

trance for the pin into the lock at that moment in which the lagging iron has reached the position illustrated tin Figure 13, in which the bolt holes of the fork and tongue register with one another. Subsequently the push-in device can be transferred to the bolt in order to serve the latter.

" Figure 16 shows an appropriately similar push-in device as the Figures 14 and 15, applied to coupling pin 55' of a lagging iron lock illustrated in part, in which'the tensioned push-in device is not locked by the tongueof the lagging iron to be advanced, but by means of a brace 66, which can be released by the operator (by mansof a rod or chain) who is tilting the lagging iron tobe ad- I vanced, up at its end for the purpose of releasing the push-in device at the appropriate moment, from a dis tance;

To simplify the unlocking of the brace 66 a remote controlled device is used, for example a bell crank lever mounted on the lagging iron to be advanced, which in the illustration is not shown, and which when raising the lagging iron to be advanced knocks the brace 66 away from its position shown in Figure 16, and thereby releases the spring 12.

In Figure 14 moreover an embodiment is shown in chain-dotted lines which differs from the embodiments of the push-in device described. The same consists of a rodor leaf-spring 73 attached at one end by means of a projecting body 72 on the lagging iron 52, and engaging at the other end on the head of the bolt 56 to be pushed in.

As shown, this spring is bent in the non-tensioned condition towards th lagging iron. By bending the spring in the opposite direction the same is tensioned and can then be locked, if desired, by means of a brace similar to the one illustrated in Figure 16.

The devices described hereinbefore with reference to Figures 13 to 16 can be used also for facilitating the operation of dismantling in basically the same manner, by reversing the direction of the action in an appropriately adapted or modified construction. Its operation can be effected in one case as in the other purely mechanically or in a different manner, for instance by means of. compressed air.

The invention is not limited to the embodiments described in detail hereinbefore and illustrated in the drawings, but numerous modifications thereof are possible, without departing from its basic idea.

I claim:

1. In a lagging iron construction, a first and a second iron, said first iron having a tongue on one of its ends, said tongue having a recess with two faces, said second iron having a fork on One of its ends and a transverse aperture at the root of said fork alignable with said recess, the width of said recess being smaller than the width of said aperture, pivot means to rotatably mount said tongue in said fork, a locking plate slidably positioned in said aperture and having a face adjacent to said tongue, and a ridge on said plate face integral with said plate and extending in substantially diagonal direction thereon, said ridge having at least two faces, one of said faces selectively resting against one of said recess faces, the width of said recess being larger than the distance between said ridge faces. 2. A device according to claim 1 in which the recess faces are so spaced with respect to the thickness of said ridge that said locking plate may be moved a substantial part of its length between locking positions with said faces.

3. The lagging iron construction according to claim 1 in which the contacting faces of said plate ridge and said recesses are profiled to mesh in a manner of involute cycloid gear teeth,

4. A lagging iron construction according to claim 1 in which said tongue end is provided with a hooked surface adapted to engage a removable pin transversely disposed on said fork to provid initial support for pivoting the lagging iron into coupling position between said tongue and said fork of the other lagging iron.

5. A device according to claim 1 in which the said fork and tongue carry markers which are in horizontal alignment when the apertures for said coupling means are in registry.

6. A device according to claim 1 in which the tongue carries a removable stop element and said fork carries a projection at its end to abut said element when the apertures for the coupling means are in registry.

7. A device according to claim 1 in which said locking plate is provided with lateral projections on its transverse ends and a retractable element mounted in the root of said fork providing an abutment for said projections to secure said plate in the lock and upon retraction to permit removal thereof.

8. A device according to claim 7 in which said retractable element comprises a resilient member adjustable into contact with said plate to provide a braking action thereon.

9. A device according to claim 1 in which the oblique ridge on said plate extends from end to end thereof.

10. A device according to claim 1 in which said locking plate is provided with separate off-set ridges extending from each transverse end thereof and spaced apart in the central portion of said plate toallow passage of the end of said tongue,

11. A connection of locking irons according to claim 1, wherein a detachable chain connects the two lagging irons with one another and is attached to said lagging irons by means of a stirrup.

12. A connection of lagging irons according to claim 1 including resilient means operatively connected to said plate and acting thereon in the direction of the axis of said pivot means to push said plate into said aperture in said fork.

13. A device according to claim 1 wherein said plate has two terminal positions, including spring means connected to sad' plate and to at least one of said irons, said spring means being under tension when said plate is in one of its terminal transverse positions to push said plate towards the other of said terminal positions.

14. A device according to claim 13 including a rod interconnecting said plate and said spring means, saidrod extending in the direction of force exerted by" said spring means upon said plate.

15. A device according to claim 14 wherein said spring means comprises two coil springs symmetrically disposed at said rod, means to connect one of said coil springs to one of said irons, and means to connect the other of said springs to said other one of said irons.

16. In a lagging iron construction, a first and a second iron, said first iron having a tongu on one of its ends, said second iron having a fork on one of its ends, means to pivotally mount said tongue on said fork, said fork including an aperture extending substantially perpendicular to the plane of rotation of said pivot means, a locking plate slidably positioned in said aperture, said locking plate having a face adjacent to said tongue, and a ridge on said face extending in substantially diagonal direction thereon, said ridge positively resting against a surface portion of said tongue and permitting an angle between said tongue and said fork dependent upon the transverse position of said locking plate.

17. In a connection of lagging irons having lock components mutually engaging by means of a fork and tongue joint and connected rotatably about a horizontal axis with one another, and which can be locked against one another in any angular position of the lagging irons with respect to one another within the required range of use by means of a transversely shiftable plate, the improvement which comprises resilient means in the, root of the fork engaging the transverse plate, a ridge on said plate extending diagonally on the face of said plate fr m end to end thereof, two contact faces on said ridge, two counter-faces formed by a recess in the end of the tongue, one face cooperating with one counter-face in one position of the lagging irons and theother face cooperating with the other counter-face in the lagging iron position turned thereof, and resting-in means on the tongue and fork which in the arcuate coupling position of the lagging irons are juxtaposed to each other.

18. In a connection of lagging irons having lock components mutually engaging by means of a fork and tongue joint and connected rotatably about a horizontal axis with one another and which can be locked against one another in any angular position of the lagging irons with respect to one another within the required range of use by means of a transversely shiftable plate, the improve- 13 ment which comprises a resilient means in the root of the fork engaging the transverse plate, two parallel ridges on a face of said plate, each of said ridges having two contacting faces, two counter-faces formed by a recess in the end of the tongue, one face of one ridge cooperating 5 with one counter-face in one position of the lagging iron and one face of the other ridge cooperating with the other counter-face in the lagging iron position turned 180 thereof, and a gap between said ridges permitting the passage of the tongue.

References Cited in the file of this patent FOREIGN PATENTS Germany Mar. 13, 1952 Great Britain Mar. 19, 1952 Belgium Oct. 31, 1952 Belgium Dec. 1, 1952 Germany Dec. 29, 1952 Belgium Jan. 31, 1953 Germany Nov. 19, 1953 Belgium Feb. 15, 1954 

